4 * Implements the architecture independant portion of the LWKT
7 * Types which must already be defined when this header is included by
8 * userland: struct md_thread
10 * $DragonFly: src/sys/sys/thread.h,v 1.97 2008/09/20 04:31:02 sephe Exp $
13 #ifndef _SYS_THREAD_H_
14 #define _SYS_THREAD_H_
16 #ifndef _SYS_STDINT_H_
17 #include <sys/stdint.h> /* __int types */
20 #include <sys/param.h> /* MAXCOMLEN */
23 #include <sys/queue.h> /* TAILQ_* macros */
25 #ifndef _SYS_MSGPORT_H_
26 #include <sys/msgport.h> /* lwkt_port */
29 #include <sys/time.h> /* struct timeval */
31 #ifndef _SYS_SPINLOCK_H_
32 #include <sys/spinlock.h>
34 #ifndef _SYS_IOSCHED_H_
35 #include <sys/iosched.h>
37 #ifndef _MACHINE_THREAD_H_
38 #include <machine/thread.h>
56 typedef struct lwkt_queue *lwkt_queue_t;
57 typedef struct lwkt_token *lwkt_token_t;
58 typedef struct lwkt_tokref *lwkt_tokref_t;
59 typedef struct lwkt_cpu_msg *lwkt_cpu_msg_t;
60 typedef struct lwkt_cpu_port *lwkt_cpu_port_t;
61 typedef struct lwkt_ipiq *lwkt_ipiq_t;
62 typedef struct lwkt_cpusync *lwkt_cpusync_t;
63 typedef struct thread *thread_t;
65 typedef TAILQ_HEAD(lwkt_queue, thread) lwkt_queue;
68 * Differentiation between kernel threads and user threads. Userland
69 * programs which want to access to kernel structures have to define
70 * _KERNEL_STRUCTURES. This is a kinda safety valve to prevent badly
71 * written user programs from getting an LWKT thread that is neither the
72 * kernel nor the user version.
74 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
75 #ifndef _MACHINE_THREAD_H_
76 #include <machine/thread.h> /* md_thread */
78 #ifndef _MACHINE_FRAME_H_
79 #include <machine/frame.h>
86 * Tokens are used to serialize access to information. They are 'soft'
87 * serialization entities that only stay in effect while a thread is
88 * running. If the thread blocks, other threads can run holding the same
89 * token(s). The tokens are reacquired when the original thread resumes.
91 * A thread can depend on its serialization remaining intact through a
92 * preemption. An interrupt which attempts to use the same token as the
93 * thread being preempted will reschedule itself for non-preemptive
94 * operation, so the new token code is capable of interlocking against
95 * interrupts as well as other cpus. This means that your token can only
96 * be (temporarily) lost if you *explicitly* block.
98 * Tokens are managed through a helper reference structure, lwkt_tokref,
99 * which is typically declared on the caller's stack. Multiple tokref's
100 * may reference the same token.
103 typedef struct lwkt_token {
104 struct lwkt_tokref *t_ref; /* Owning ref or NULL */
107 #define LWKT_TOKEN_INITIALIZER(head) \
112 #define ASSERT_LWKT_TOKEN_HELD(tok) \
113 KKASSERT((tok)->t_ref->tr_owner == curthread)
115 typedef struct lwkt_tokref {
116 lwkt_token_t tr_tok; /* token in question */
117 struct thread *tr_owner; /* me */
118 lwkt_tokref_t tr_next; /* linked list */
121 #define MAXCPUFIFO 16 /* power of 2 */
122 #define MAXCPUFIFO_MASK (MAXCPUFIFO - 1)
123 #define LWKT_MAXTOKENS 16 /* max tokens beneficially held by thread */
126 * Always cast to ipifunc_t when registering an ipi. The actual ipi function
127 * is called with both the data and an interrupt frame, but the ipi function
128 * that is registered might only declare a data argument.
130 typedef void (*ipifunc1_t)(void *arg);
131 typedef void (*ipifunc2_t)(void *arg, int arg2);
132 typedef void (*ipifunc3_t)(void *arg, int arg2, struct intrframe *frame);
134 typedef struct lwkt_ipiq {
135 int ip_rindex; /* only written by target cpu */
136 int ip_xindex; /* written by target, indicates completion */
137 int ip_windex; /* only written by source cpu */
138 ipifunc3_t ip_func[MAXCPUFIFO];
139 void *ip_arg1[MAXCPUFIFO];
140 int ip_arg2[MAXCPUFIFO];
141 u_int ip_npoll; /* synchronization to avoid excess IPIs */
145 * CPU Synchronization structure. See lwkt_cpusync_start() and
146 * lwkt_cpusync_finish() for more information.
148 typedef void (*cpusync_func_t)(lwkt_cpusync_t poll);
149 typedef void (*cpusync_func2_t)(void *data);
151 struct lwkt_cpusync {
152 cpusync_func_t cs_run_func; /* run (tandem w/ acquire) */
153 cpusync_func_t cs_fin1_func; /* fin1 (synchronized) */
154 cpusync_func2_t cs_fin2_func; /* fin2 (tandem w/ release) */
157 volatile int cs_count;
162 * The standard message and queue structure used for communications between
163 * cpus. Messages are typically queued via a machine-specific non-linked
164 * FIFO matrix allowing any cpu to send a message to any other cpu without
167 typedef struct lwkt_cpu_msg {
168 void (*cm_func)(lwkt_cpu_msg_t msg); /* primary dispatch function */
169 int cm_code; /* request code if applicable */
170 int cm_cpu; /* reply to cpu */
171 thread_t cm_originator; /* originating thread for wakeup */
175 * Thread structure. Note that ownership of a thread structure is special
176 * cased and there is no 'token'. A thread is always owned by the cpu
177 * represented by td_gd, any manipulation of the thread by some other cpu
178 * must be done through cpu_*msg() functions. e.g. you could request
179 * ownership of a thread that way, or hand a thread off to another cpu.
181 * NOTE: td_pri is bumped by TDPRI_CRIT when entering a critical section,
182 * but this does not effect how the thread is scheduled by LWKT.
184 * NOTE: td_ucred is synchronized from the p_ucred on user->kernel syscall,
185 * trap, and AST/signal transitions to provide a stable ucred for
186 * (primarily) system calls. This field will be NULL for pure kernel
193 TAILQ_ENTRY(thread) td_threadq;
194 TAILQ_ENTRY(thread) td_allq;
195 TAILQ_ENTRY(thread) td_sleepq;
196 lwkt_port td_msgport; /* built-in message port for replies */
197 struct lwp *td_lwp; /* (optional) associated lwp */
198 struct proc *td_proc; /* (optional) associated process */
199 struct pcb *td_pcb; /* points to pcb and top of kstack */
200 struct globaldata *td_gd; /* associated with this cpu */
201 const char *td_wmesg; /* string name for blockage */
202 const volatile void *td_wchan; /* waiting on channel */
203 int td_pri; /* 0-31, 31=highest priority (note 1) */
204 int td_flags; /* TDF flags */
205 int td_wdomain; /* domain for wchan address (typ 0) */
206 void (*td_preemptable)(struct thread *td, int critpri);
207 void (*td_release)(struct thread *td);
208 char *td_kstack; /* kernel stack */
209 int td_kstack_size; /* size of kernel stack */
210 char *td_sp; /* kernel stack pointer for LWKT restore */
211 void (*td_switch)(struct thread *ntd);
212 __uint64_t td_uticks; /* Statclock hits in user mode (uS) */
213 __uint64_t td_sticks; /* Statclock hits in system mode (uS) */
214 __uint64_t td_iticks; /* Statclock hits processing intr (uS) */
215 int td_locks; /* lockmgr lock debugging */
217 void *td_dsched_priv1; /* priv data for I/O schedulers */
218 int td_refs; /* hold position in gd_tdallq / hold free */
219 int td_nest_count; /* prevent splz nesting */
221 int td_mpcount; /* MP lock held (count) */
222 int td_cscount; /* cpu synchronization master */
224 int td_mpcount_unused; /* filler so size matches */
225 int td_cscount_unused;
227 struct iosched_data td_iosdata; /* Dynamic I/O scheduling data */
228 struct timeval td_start; /* start time for a thread/process */
229 char td_comm[MAXCOMLEN+1]; /* typ 16+1 bytes */
230 struct thread *td_preempted; /* we preempted this thread */
231 struct ucred *td_ucred; /* synchronized from p_ucred */
232 struct caps_kinfo *td_caps; /* list of client and server registrations */
233 lwkt_tokref_t td_toks; /* tokens beneficially held */
234 #ifdef DEBUG_CRIT_SECTIONS
235 #define CRIT_DEBUG_ARRAY_SIZE 32
236 #define CRIT_DEBUG_ARRAY_MASK (CRIT_DEBUG_ARRAY_SIZE - 1)
237 const char *td_crit_debug_array[CRIT_DEBUG_ARRAY_SIZE];
238 int td_crit_debug_index;
239 int td_in_crit_report;
241 struct md_thread td_mach;
245 * Thread flags. Note that TDF_RUNNING is cleared on the old thread after
246 * we switch to the new one, which is necessary because LWKTs don't need
247 * to hold the BGL. This flag is used by the exit code and the managed
248 * thread migration code. Note in addition that preemption will cause
249 * TDF_RUNNING to be cleared temporarily, so any code checking TDF_RUNNING
250 * must also check TDF_PREEMPT_LOCK.
252 * LWKT threads stay on their (per-cpu) run queue while running, not to
253 * be confused with user processes which are removed from the user scheduling
254 * run queue while actually running.
256 * td_threadq can represent the thread on one of three queues... the LWKT
257 * run queue, a tsleep queue, or an lwkt blocking queue. The LWKT subsystem
258 * does not allow a thread to be scheduled if it already resides on some
261 #define TDF_RUNNING 0x0001 /* thread still active */
262 #define TDF_RUNQ 0x0002 /* on an LWKT run queue */
263 #define TDF_PREEMPT_LOCK 0x0004 /* I have been preempted */
264 #define TDF_PREEMPT_DONE 0x0008 /* acknowledge preemption complete */
265 #define TDF_IDLE_NOHLT 0x0010 /* we need to spin */
266 #define TDF_MIGRATING 0x0020 /* thread is being migrated */
267 #define TDF_SINTR 0x0040 /* interruptability hint for 'ps' */
268 #define TDF_TSLEEPQ 0x0080 /* on a tsleep wait queue */
270 #define TDF_SYSTHREAD 0x0100 /* allocations may use reserve */
271 #define TDF_ALLOCATED_THREAD 0x0200 /* objcache allocated thread */
272 #define TDF_ALLOCATED_STACK 0x0400 /* objcache allocated stack */
273 #define TDF_VERBOSE 0x0800 /* verbose on exit */
274 #define TDF_DEADLKTREAT 0x1000 /* special lockmgr deadlock treatment */
275 #define TDF_STOPREQ 0x2000 /* suspend_kproc */
276 #define TDF_WAKEREQ 0x4000 /* resume_kproc */
277 #define TDF_TIMEOUT 0x8000 /* tsleep timeout */
278 #define TDF_INTTHREAD 0x00010000 /* interrupt thread */
279 #define TDF_TSLEEP_DESCHEDULED 0x00020000 /* tsleep core deschedule */
280 #define TDF_BLOCKED 0x00040000 /* Thread is blocked */
281 #define TDF_PANICWARN 0x00080000 /* panic warning in switch */
282 #define TDF_BLOCKQ 0x00100000 /* on block queue */
283 #define TDF_MPSAFE 0x00200000 /* (thread creation) */
284 #define TDF_EXITING 0x00400000 /* thread exiting */
285 #define TDF_USINGFP 0x00800000 /* thread using fp coproc */
286 #define TDF_KERNELFP 0x01000000 /* kernel using fp coproc */
287 #define TDF_NETWORK 0x02000000 /* network proto thread */
290 * Thread priorities. Typically only one thread from any given
291 * user process scheduling queue is on the LWKT run queue at a time.
292 * Remember that there is one LWKT run queue per cpu.
294 * Critical sections are handled by bumping td_pri above TDPRI_MAX, which
295 * causes interrupts to be masked as they occur. When this occurs a
296 * rollup flag will be set in mycpu->gd_reqflags.
298 #define TDPRI_IDLE_THREAD 0 /* the idle thread */
299 #define TDPRI_USER_SCHEDULER 2 /* user scheduler helper */
300 #define TDPRI_USER_IDLE 4 /* user scheduler idle */
301 #define TDPRI_USER_NORM 6 /* user scheduler normal */
302 #define TDPRI_USER_REAL 8 /* user scheduler real time */
303 #define TDPRI_KERN_LPSCHED 9 /* scheduler helper for userland sch */
304 #define TDPRI_KERN_USER 10 /* kernel / block in syscall */
305 #define TDPRI_KERN_DAEMON 12 /* kernel daemon (pageout, etc) */
306 #define TDPRI_SOFT_NORM 14 /* kernel / normal */
307 #define TDPRI_SOFT_TIMER 16 /* kernel / timer */
308 #define TDPRI_EXITING 19 /* exiting thread */
309 #define TDPRI_INT_SUPPORT 20 /* kernel / high priority support */
310 #define TDPRI_INT_LOW 27 /* low priority interrupt */
311 #define TDPRI_INT_MED 28 /* medium priority interrupt */
312 #define TDPRI_INT_HIGH 29 /* high priority interrupt */
315 #define TDPRI_MASK 31
316 #define TDPRI_CRIT 32 /* high bits of td_pri used for crit */
319 #define LWKT_THREAD_STACK (UPAGES * PAGE_SIZE)
322 #define CACHE_NTHREADS 6
324 #define IN_CRITICAL_SECT(td) ((td)->td_pri >= TDPRI_CRIT)
326 extern void lwkt_init(void);
327 extern struct thread *lwkt_alloc_thread(struct thread *, int, int, int);
328 extern void lwkt_init_thread(struct thread *, void *, int, int,
329 struct globaldata *);
330 extern void lwkt_set_comm(thread_t, const char *, ...);
331 extern void lwkt_wait_free(struct thread *);
332 extern void lwkt_free_thread(struct thread *);
333 extern void lwkt_gdinit(struct globaldata *);
334 extern void lwkt_switch(void);
335 extern void lwkt_preempt(thread_t, int);
336 extern void lwkt_schedule(thread_t);
337 extern void lwkt_schedule_noresched(thread_t);
338 extern void lwkt_schedule_self(thread_t);
339 extern void lwkt_deschedule(thread_t);
340 extern void lwkt_deschedule_self(thread_t);
341 extern void lwkt_yield(void);
342 extern void lwkt_user_yield(void);
343 extern void lwkt_token_wait(void);
344 extern void lwkt_hold(thread_t);
345 extern void lwkt_rele(thread_t);
346 extern void lwkt_passive_release(thread_t);
348 extern void lwkt_gettoken(lwkt_tokref_t, lwkt_token_t);
349 extern int lwkt_trytoken(lwkt_tokref_t, lwkt_token_t);
350 extern void lwkt_gettokref(lwkt_tokref_t);
351 extern int lwkt_trytokref(lwkt_tokref_t);
352 extern void lwkt_reltoken(lwkt_tokref_t);
353 extern int lwkt_getalltokens(thread_t);
354 extern void lwkt_relalltokens(thread_t);
355 extern void lwkt_drain_token_requests(void);
356 extern void lwkt_token_init(lwkt_token_t);
357 extern void lwkt_token_uninit(lwkt_token_t);
359 extern void lwkt_token_pool_init(void);
360 extern lwkt_token_t lwkt_token_pool_lookup(void *);
361 extern void lwkt_getpooltoken(lwkt_tokref_t, void *);
363 extern void lwkt_setpri(thread_t, int);
364 extern void lwkt_setpri_initial(thread_t, int);
365 extern void lwkt_setpri_self(int);
366 extern int lwkt_check_resched(thread_t);
367 extern void lwkt_setcpu_self(struct globaldata *);
368 extern void lwkt_migratecpu(int);
372 extern void lwkt_giveaway(struct thread *);
373 extern void lwkt_acquire(struct thread *);
374 extern int lwkt_send_ipiq3(struct globaldata *, ipifunc3_t, void *, int);
375 extern int lwkt_send_ipiq3_passive(struct globaldata *, ipifunc3_t,
377 extern int lwkt_send_ipiq3_nowait(struct globaldata *, ipifunc3_t,
379 extern int lwkt_send_ipiq3_bycpu(int, ipifunc3_t, void *, int);
380 extern int lwkt_send_ipiq3_mask(cpumask_t, ipifunc3_t, void *, int);
381 extern void lwkt_wait_ipiq(struct globaldata *, int);
382 extern int lwkt_seq_ipiq(struct globaldata *);
383 extern void lwkt_process_ipiq(void);
385 extern void lwkt_process_ipiq_frame(struct intrframe *);
387 extern void lwkt_smp_stopped(void);
388 extern void lwkt_synchronize_ipiqs(const char *);
392 extern void lwkt_cpusync_simple(cpumask_t, cpusync_func_t, void *);
393 extern void lwkt_cpusync_fastdata(cpumask_t, cpusync_func2_t, void *);
394 extern void lwkt_cpusync_start(cpumask_t, lwkt_cpusync_t);
395 extern void lwkt_cpusync_add(cpumask_t, lwkt_cpusync_t);
396 extern void lwkt_cpusync_finish(lwkt_cpusync_t);
398 extern void crit_panic(void);
399 extern struct lwp *lwkt_preempted_proc(void);
401 extern int lwkt_create (void (*func)(void *), void *, struct thread **,
402 struct thread *, int, int, const char *, ...);
403 extern void lwkt_exit (void) __dead2;
404 extern void lwkt_remove_tdallq (struct thread *);